JP2739152B2 - Reactive adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reactive pressure-sensitive adhesive composition which is cured by heat. More specifically, this composition is a reactive pressure-sensitive adhesive composition which is initially tacky, but which is cured by heat to produce adhesion. The adhesive tape has adhesiveness at room temperature, and can be attached to an object without any preparatory operation. In addition, they are used in various fields because of the advantage that they can be reattached. However, adhesive tapes have the disadvantage that their adhesive strength is generally weaker than adhesives. In addition, usually, since the tape is formed by applying an adhesive to the tape base, the tape has a complicated shape, for example, a stepped portion, a dent or a protruding portion, the base material is not provided. Due to the thickness, hardness, waist, and the like, it is impossible to attach them without gaps. The adhesive tape also has problems in water resistance, solvent resistance and heat resistance. On the other hand, paints, adhesives, sealants, etc. have complex shapes,
It is applicable to curved surfaces, holes, protrusions, steps, gaps, and the like, and can also utilize a curing reaction, which is advantageous in improving water resistance, solvent resistance, and heat resistance. However, these require a pretreatment, such as mixing a curing agent before use, and are usually in the form of a sol or paste contained in a solvent. It is troublesome because it must be in a container on the surface. Also, care must be taken to prevent contamination of parts other than the target location due to flow, dripping, and splashing during construction, and once contaminated, removal is extremely complicated and often impossible. In view of the above circumstances, the good point of the pressure-sensitive adhesive and the good point of the paint, the adhesive, and the sealer have only the good point, and as a result of diligent efforts to obtain a product that eliminates these disadvantages, the present invention has been completed. . What was invented in the present invention,
It has an adhesive strength that can be applied to the target without any preparatory operation and fixed until curing is completed.In addition, it can be re-attached without any contamination even if it fails once, and after it is cured by heating means Quality similar to that of paints, adhesives, sealers, protective film formers, or organic powder binders
It has performance. Until now, thermosetting sheets, hot melt adhesives, and the like have already been marketed, but none of them have adhesiveness under normal conditions and harden. The present invention has a viscosity of 10 ² c at room temperature (15 to 25 ° C .;
It is characterized by containing a curable resin mainly composed of an acrylic urethane oligomer having a ps or more and a saturated polyester resin which has cohesive strength and is solid at ordinary temperature. From these combinations, those having appropriate adhesive properties at room temperature, that is, having initial tack, holding power, and adhesive strength, can be easily cured by heat, and have extremely tough or elastic physical properties after curing. I got it. A feature of the present invention is that tackiness is provided without using a low molecular weight tackifying resin at all. Therefore, it has excellent solvent resistance and heat resistance after curing. Low molecular weight oligomers of reactive (meth) acrylate resins have poor cohesion at room temperature, even if solid. Also, the saturated polyester resin does not itself react like the reactive low molecular weight acrylate. The present inventors have succeeded in obtaining a curable composition having tackiness in a normal state by combining these two resins. The oligomer of the reactive (meth) acrylate resin used in the present invention is a liquid or a solid having a viscosity at room temperature of 10 ² cps or more, while the cohesive saturated polyester resin has a glass transition point at room temperature or lower. It is a resin that is solid under certain conditions. The required amounts of both resins are mixed and melted to uniformly disperse or dissolve to obtain the reactive pressure-sensitive adhesive of the present invention. The obtained product has no fluidity at room temperature and has appropriate tackiness and cohesion, so that it can be supplied in any form. For example, the shape is a string, a pellet, a sheet, or a block. As a curing method, a curing catalyst such as a suitable thermosetting agent can be added to the above composition. In the case of heat, the curing temperature is appropriately adjusted. The composition to which the curing catalyst has been added is, for example, spread on release paper to form a sheet of a reactive pressure-sensitive adhesive, and after the sheet is attached to an adherend, the release paper is peeled off and heated to cure. Thick coating. Also, if this reactive adhesive is applied to the joints and recesses of the iron plate, it becomes a substitute for the conventional sealant, putty used for filling holes, filling, and water sealing of window frames. Sealing can be easily performed even where the application of the agent or the like is difficult. In addition, even if this reactive adhesive is applied to the application section and before it is cured, it can be removed cleanly without contaminating the application section, so that it can be reapplied, greatly improving workability. Hereinafter, an embodiment will be described. Example 1 Saturated polyester Byron 200 70 parts Urethane acrylate Alonix M-1100 200 to 300,000 cps / 50 ° C 30 parts (Toa Gosei Chemical Industry KK) Silica fine powder Aerosil R-972 20 parts (Nippon Aerosil KK) Pigment Titanium white Average Particle size 0.5 μm 20 parts Isobutyl peroxide 1 part The above-mentioned raw materials were mixed by a kneader and poured into a silicon rubber mold of an emblem taken from an automobile body using an injection molding machine. After cooling, the molded emblem was removed from the silicone rubber mold. When this molded emblem was attached to the body of an automobile and heated and cured at 140 ° C. for 20 minutes, the molded emblem was hardened and firmly adhered to the body. When the paint was sprayed from above, the adhesion was further improved. Further, a phosphor was mixed with the above-mentioned compounding raw material, and a molded article having the same emblem shape was prepared and affixed to a vehicle body.
When the emblem was affixed, it glowed fluorescently when it was dark, and the letters appeared. [Example 2] 70 parts of saturated polyester LP-022 (Nippon Synthetic Chemical Industry KK) Urethane acrylate biscoat 812 30 parts 1000-1900 cps / 50 ° C 8000-100,000 cps / 23 ° C (Osaka Organic Chemical Industry KK) Isobutyl peroxide 1 part Urethane 50 parts of resin fine powder (maximum particle diameter: 50 μm) After uniformly kneading the composition having the above composition, it was spread on a 25 μm-thick polyester (PET) film to a thickness of 1 mm to obtain a reactive pressure-sensitive adhesive sheet. The pressure-sensitive adhesive surface of the obtained sheet was tacky, but lacked fluidity. A part of the sheet was cut out, affixed to a cold-rolled steel plate (SPCC-B), peeled off the PET film, heated and cured at 140 ° C for 20 minutes, and the surface was non-adhesive. When sandpaper was applied to the surface, the surface was polished without clogging. And the above sheet
The sheet was cooled to 20 ° C., wound around a rod having a diameter of 20 mm, and even if the sheet was bent at an appropriate angle, no crack was generated in the sheet. [Example 3] Saturated polyester Byron 300 40 parts (Toyobo KK) Urethane acrylate Ubisan 893 60 parts 1900 cps / 50 ° C 7500 to 100000 cps / 23 ° C (KK thiochol) Benzoyl peroxide 0.5 parts Talc 20 parts The composition having the above composition was kneaded. Then, the mixture was passed through a film extruder to obtain a sheet having a thickness of 1 mm and having adhesiveness at room temperature. Cut the obtained sheet into 20mm width and cut it into thickness
Attached to the edge of 0.8mm steel plate (SPCC-B), 140 ℃
Heated for 20 minutes. The corners of the attached sheet were melted and rounded, and cured in that state. The surface was shiny and smooth. 3% of the steel sheet covering the edge
The spray test was continuously performed for 144 hours using an aqueous solution of sodium chloride, but no rust was observed at the sealed edge portion. In each of the above examples, Byron, Aronix, Aerosil, Biscote, and Ubisan are all trademarks.

   ────────────────────────────────────────────────── ─── Continuation of front page    (56) References JP-A-60-13868 (JP, A)                 JP-A-59-176370 (JP, A)                 JP-A-63-210182 (JP, A)                 JP-A-50-140538 (JP, A)                 JP-A-48-26232 (JP, A)                 JP-A-54-28384 (JP, A)

Claims (1)

(57) [Claims] It contains a saturated polyester resin that is solid at room temperature, a (meth) acrylic urethane oligomer having a viscosity of 10 ² cps or more at room temperature, and a thermosetting catalyst. The mixture is kneaded without adding a solvent. A reactive pressure-sensitive adhesive composition having a property and being cured by heating. 2. It contains a saturated polyester resin that is solid at room temperature, a (meth) acrylic urethane oligomer having a viscosity of 10 ² cps or more at room temperature, a thermosetting catalyst, and further includes a magnetic material, a conductor, a dielectric, a phosphor, a pigment, and an organic compound. Reactive adhesive containing at least one selected from resin fine powder, inorganic powder and metal powder, obtained by kneading these without adding a solvent, has tackiness at room temperature, and cures when heated. Composition.